Tornadoes · United States · Nebraska · 2023

EF1 tornado, Anselmo, Nebraska, May 12, 2023

This EF1 tornado ran 4.0 miles across Custer County on May 12, 2023, touching down at 12:34 PM CDT and reaching 100 yards wide. It killed nobody.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. EF065 to 85 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. EF186 to 110 mphthis tornado

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. EF2111 to 135 mph

    Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

  4. EF3136 to 165 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. EF4166 to 200 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. EF5over 200 mph

    Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

  7. Unrated

    The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The record

Rating
EF1
Date
May 12, 2023
Touchdown
12:34 PM CDT (17:34 UTC)
Lifted
12:48 PM CDT (17:48 UTC)
On the ground
14 minutes
Path length
4.0 miles (6.5 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
County
Custer County
Touchdown point
41.620, -99.870
Lift-off point
41.661, -99.925
Record number
2305121134-01

The damage survey

15 damage points were recorded along this path by NWS LBF, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 110 mph.

  • Start point of tornado. Pivots flipped, small pine tree damage.
  • Non DI. Flipped irrigation pivot system
  • Snapped healthy hardwood tree.
  • Snapped healthy pine tree.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

What the Weather Service recorded

A closed low pressure system moved slowly across the northern Plains and spawned multiple tornadoes across north central Nebraska.

The tornado move to the northwest, causing extensive tree damage on the west side of Anselmo.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
17:20 UTC17:28 UTCFlood AdvisoryLBF
17:28 UTC22:06 UTCFlood WarningLBF
17:37 UTC18:15 UTCTornado WarningLBF
17:49 UTC18:30 UTCTornado WarningLBF
18:10 UTC22:42 UTCTornado WatchLBF
20:56 UTC21:30 UTCTornado WarningLBF
22:06 UTC11:11 UTCFlood AdvisoryLBF

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The forecast that day

The Storm Prediction Center had this point in a Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 16:19 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

N. Platte/Lee Bi, NE (KLBF), 12:00Z

5.6 hours before the tornado, 82 km from the path. May 12, 2023.

Skew-T log-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 12:00Z on 2023-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 96 joules per kilogram, CIN -70, lifted condensation level 1068 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, N. Platte/Lee Bi, NE at 12:00Z on 2023-05-12The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 145 square meters per square second, 0 to 6 km bulk shear 30 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
96 J/kg
Mixed-layer CIN
-70 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1068 m above ground
0-6 km bulk shear
30 kt
0-1 km bulk shear
18 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
204 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
4.9 K/km

Open this sounding in Storm Lab

N. Platte/Lee Bi, NE (KLBF), 00:00Z

6.4 hours after it, 82 km from the path. May 13, 2023.

Skew-T log-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 00:00Z on 2023-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -61, lifted condensation level 1009 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, N. Platte/Lee Bi, NE at 00:00Z on 2023-05-13The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity -43 square meters per square second, 0 to 6 km bulk shear 4 knots.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
-61 J/kg
Surface CAPE
299 J/kg
Mixed-layer LCL
1009 m above ground
0-6 km bulk shear
4 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
-43 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.1 K/km

Open this sounding in Storm Lab

The radar

The North Platte radar (KLNX), 66 km away, was scanning. The volume nearest the touchdown began at 17:34 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
17:42 UTCTORNADO4 N ArnoldCuster, NECUSTER COUNTY EMERGENCY MANAGER REPORTS A TORNADO ON THE GROUND. HAS SINCE LIFTED.
17:47 UTCTORNADO5 Nnw ArnoldCuster, NEBRIEF TORNADO TOUCHDOWN.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2023 tornado in NebraskaEvery tornado in Nebraska since 1950Warnings in force in Nebraska nowThe forecast where you are

The other tornadoes of May 12, 2023

32 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 1212:39 PM CDTUnratedLogan, NE0.110
May 1212:42 PM CDTUnratedCuster, NE0.11
May 1212:47 PM CDTUnratedCuster, NE0.110
May 122:25 PM CDTEF1Greeley, NE13.6200$300,000
May 123:11 PM CDTEF1Wheeler, NE3.450
May 123:25 PM CDTUnratedWheeler, NE0.150
May 123:55 PM CDTUnratedPlatte, NE0.150
May 123:55 PM CDTEF2Wheeler, NE7.375
May 124:00 PM CDTUnratedCuster, NE0.110
May 124:09 PM CDTEF1Boone, NE1.3150
May 124:22 PM CDTUnratedMadison, NE0.150
May 124:33 PM CDTEF1Pawnee, NE3.080
May 124:53 PM CDTEF1Stanton, NE8.9200
May 125:01 PM CDTEF1Madison, NE3.150
May 125:15 PM CDTEF2Dodge, NE5.5800
May 125:17 PM CDTEF1Stanton, NE5.0150
May 125:34 PM CDTEF1Stanton, NE2.8200
May 125:39 PM CDTEF1Stanton, NE5.1300
May 125:42 PM CDTEF0Dodge, NE2.5300
May 125:46 PM CDTEF2Dodge, NE10.41,600
May 126:14 PM CDTEF1Burt, NE1.1100
May 126:14 PM CDTEF0Wayne, NE0.320
May 126:20 PM CDTEF2Burt, NE11.31,1502
May 126:34 PM CDTEF0Wayne, NE0.720
May 127:03 PM CDTEF2Brown, KS1.5500
May 127:11 PM CDTEF1Jackson, KS3.650
May 127:18 PM CDTEF0Brown, KS to NE2.350
May 127:23 PM CDTUnratedBurt, NE0.450
May 127:38 PM CDTUnratedJackson, KS0.010
May 127:43 PM CDTUnratedBurt, NE0.520
May 127:49 PM CDTUnratedJackson, KS0.010
May 128:06 PM CDTEF0Kay, OK0.310

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.